


Detention

by FantasticNumberNine



Series: John Watson and the Philosopher's Stone [8]
Category: Harry Potter - J. K. Rowling, Sherlock (TV)
Genre: AU, Baby Dragon, Blood Drinking, Centaurs, Crossover, Detention, Forbidden Forest, Gen, Invisibility Cloak, Potterlock, Unicorns, dead ones, grouchy mycroft
Language: English
Status: Completed
Published: 2014-07-11
Updated: 2014-07-11
Packaged: 2018-02-08 10:14:19
Rating: General Audiences
Warnings: Creator Chose Not To Use Archive Warnings
Chapters: 1
Words: 1,204
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/1937001
Author URL: https://archiveofourown.org/users/FantasticNumberNine/pseuds/FantasticNumberNine
Summary: <blockquote class="userstuff">
      <p>*disclaimer*</p><p>Mycroft is ridiculous. But he's also my favorite. I think sorting Gryffindor is doing him a world of good (...and this out of the mouth of a serpent...)</p>
    </blockquote>





	Detention

**Author's Note:**

> *disclaimer*
> 
> Mycroft is ridiculous. But he's also my favorite. I think sorting Gryffindor is doing him a world of good (...and this out of the mouth of a serpent...)

"When _Gregory_ gets out of the Hospital Wing, I am going to push him off this cursed tower--" Mycroft was muttering as he and John struggled to heave the small but heavy cage and its fire-breathing, Greg-biting, occupant up to the top of the astronomy tower, where Charlie Lestrade's friends would be coming to retrieve it under cover of darkness, all while keeping John's invisibility cloak secured around them.

"--Names a dragon _Norbert_? Honestly--"

John concentrated on his breathing, and stifling the insane urge to giggle that kept bubbling up.

"And good riddance," Mycroft grumbled as the boys stood for a moment watching Norbert the dragon being flown away, John's cloak dropped by the stair.

"We should get back."

Mycroft glowered and started down the stairs at a pace that had John jogging to keep up.

"We shouldn't have been here to start--"

"So we should have let Hagrid _keep_ Norbert in his _wooden_ house?"

"You are purposefully misunderstanding--"

"What's to _misunderstand_?"

"Just because you and _Gregory_ had a stroke of luck against a troll doesn't mean that _I_ have any desire to tangle with a _dragon_ \--"

"Hey, our luck saved your life--"

"Well, well, well, what do we have here my sweet? First years out of bed..." 

John and Mycroft froze at the foot of the stairs, they'd left the invisibility cloak behind and walked straight into Filch and Mrs. Norris. Together with Molly Hooper--who had been caught out of bounds trying to warn them about Moriarty--they'd lost Gryffindor 150 points. Even Moriarty losing 50 points from Slytherin (who had been out after hours to get them in trouble) could not console them.

Greg walked them down to the entry hall for detention, promising to wait up in the common room for when they got back. Mycroft suggested he take the detention in his stead, to which Greg easily replied, "Sure, you just take my dragon bite and we can call it even."

Together with Molly and Moriarty, John and Mycroft followed Filch outside and to the edge of the Forbidden Forest where Hagrid was waiting for them. John raised his eyebrows at Mycroft--if they were serving detention with Hagrid, it couldn't be that bad, could it?

It could.

"The forest?" Moriarty exclaimed. "In the middle of the night? When all the man-eating creatures are wandering about?"

As Filch left, Moriarty turned to Hagrid, "I am not going in there."

"Yeh are if you plan on stayin' a student here at Hogwarts."

"Students are forbidden from going into the forest, when my father hears about what you're making me do--"

"If yeh think yer father would rather yeh leave, yeh can turn around an' go back to the castle an' pack yer trunk. Go on then!"

Unfortunately for John, Moriarty stayed, and after Moriarty scared Molly into tears, Hagrid switched them. John watched angrily as Mycroft and Molly went off with Hagrid one way, and he was forced in the other direction with Moriarty and Fang. 

They had been walking about thirty minutes before John noticed a clearing ahead and signaled for Moriarty to stop. Inching forward, they saw something bright and white lying dead on the ground--the unicorn. Moriarty approached it with a look of morbid curiosity, John close behind. He had never seen anything so beautiful and sad. Liquid silver pooled around the unicorn, reflecting the bit of sky visible through the trees.

John reached out with one hand when a rustling noise sounded from the other side of the clearing and he jumped back; something tall and dark folded out of the shadows and glided to the unicorn. John, Moriarty, and Fang stood very still, petrified. The cloaked figure crouched low beside the corpse and lowered it's head and began to drink the silvery blood.

Moriarty screamed, and when he turned to run back in the direction they'd come, Fang was hot on his heels. John couldn't move as the hooded head looked up, unicorn blood dripping down its chest, and then moved towards him with unexpected quickness.

Pain like John had never known stabbed through his head, as though his scar has combusted into flames. Half blind, John stumbled backwards before falling to his knees. Something had galloped into the clearing, but it was a long moment before the pain receded enough for him to look up at the centaur--younger looking than the ones he'd met with Hagrid and Mycroft earlier.

"Are you alright?"

"Yeah... Thanks. Er, what was that?"

The centaur did not answer, appraising him, and his scar, for an uncomfortable moment.

"You are the Watson child. I am Firenze."

Then John was on his back, and after a confrontation with the centaurs he'd met earlier, he resumed his questioning.

"What was that thing you saved me from? Is it why Bane was angry?"

Firenze slowed, and minutes later stopped entirely. "John Watson, do you know what unicorn blood is used for?"

"No... We only use the hairs and horns in potions."

"Killing a unicorn is a monstrous thing. To commit such a crime, one must have nothing to lose and everything to gain. Unicorn blood will keep you alive, even if you are on the brink of death, but at a terrible price. The moment it's blood touches your lips, you live but a half life, a cursed life."

"But who would be that desperate? Isn't it better, to die, than to live cursed forever?" 

"Yes. Unless one needs only survive long enough to partake of something far stronger, something far more powerful--"

"The philosopher's stone! But... I don't understand... Who..." John looked back, thinking very hard before the feeling of ice crept down his spine. "You mean Volde--"

"John! John! Are you hurt?" Mycroft was running towards him, Hagrid close behind with the others. 

Greg had fallen asleep on a couch in the common room waiting for them, but woke up readily when John shook him and told him and Mycroft what had occurred in the forest.

"So Snape wants the stone for Voldemort... And Voldemort is waiting for him in the forest--"

"Will you _stop_ with the name?" Greg injected, wide-eyed.

"--And Firenze saved me, but he probably shouldn't have done... Bane was furious, something about not interfering with what the planets are saying--likely about Voldemort's return... And Bane thought Firenze should have just let Voldemort kill me--that's probably written in the stars too--"

" _Stop saying his name_!"

"Now I'm what, supposed to wait while Snape steals the stone and Voldemort comes to finish what he started with me?"

Mycroft stared at him, his face a study of terror and annoyance. "John, everyone knows that Dumbledore is the only person He-Who-Must-Not-Be-Named ever feared. So as long as Dumbledore is here, he's not going to touch you. You're speculating based on something said by a centaur, who receives his information reading the skies." At that, annoyance won out, wiping away any trace of fear. " _Mars is bright tonight_ , honestly."

The boys went to bed at dawn, having stayed up talking far later than they ought to have. Crawling into bed, John found his invisibility cloak folded between his sheets with a small note pinned on:

_Just in case._


End file.
